membrain

Noun

membrane (countable and uncountable, plural membranes)

1. A mechanical, thin, flat flexible part that can deform or vibrate when excited by an external force.
2. A flexible or semiflexible covering or waterproofing whose primary function is to exclude water.
   • The animal was breathing oxygen that permeated from the water through panels of membrane while carbon dioxide and other unwanted gases moved in the opposite direction—from the animal's enclosed atmosphere into the water.1964 October 2, “SYNTHETIC FILM CAN ACT AS GILL; Silicone Rubber Membrane Is Announced by G. E.”, in The New York Times, New York, N.Y.: The New York Times Company, →ISSN, →OCLC, archived from the...
3. A microscopic double layer of lipids and proteins forming the boundary of cells or organelles.
4. A piece of parchment forming part of a roll.